Development and Testing of an Elastocaloric Cooling and Heat-Pumping Device

The pursuit of sustainable and energy-efficient cooling and heating technologies has gained increasing importance in the context of mitigating climate change and addressing the growing global cooling and heating demands. Our study focuses on the development and construction of an innovative elastocaloric cooling and heat-pumping device, which is environmentally friendly and potentially highly efficient. It is based on the elastocaloric effect, a thermodynamic phenomenon characterized by reversible temperature and/or entropy changes in superelastic shape memory alloys (SMAs) upon the application of mechanical stress. The elastocaloric device is built around four phase-shifted elastocaloric regenerators, which are porous structures made of SMAs (also known as elastocaloric materials) through which a heat transfer medium (water) is pumped in a counterflow direction between the heat sink and heat source. The elastocaloric regenerators are loaded in compression and have been demonstrated to exhibit fatigue-resistant operation and high performance with temperature spans of up to 30 K and cooling/heating power of up to 4500 W per kg of elastocaloric material. In the elastocaloric device, the regenerators are driven (loaded-unloaded) by an innovative cam-disc design, which allows for efficient recovery of the energy released upon unloading of the regenerators. This reduces the required torque and is fundamental to achieving highly efficient operation. The targeted cooling/heating power of the device is 200 W, which is already sufficient for certain market applications.